scholarly journals Characteristics of air bubbles and hydrates in the Dome Fuji ice core, Antarctica

1999 ◽  
Vol 29 ◽  
pp. 207-210 ◽  
Author(s):  
Hideki Narita ◽  
Nobuhiko Azuma ◽  
Takeo Hondoh ◽  
Michiko Fujii ◽  
Mituo Kawaguchi ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Ice Core ◽  
Air Bubbles ◽  
Depth Range ◽  
Last Interglacial ◽  
Last Glacial ◽  
Maximum Period ◽  
Glacial Periods ◽  
The Last Glacial Maximum ◽  
The Last Glacial

AbstractAir bubbles trapped near the surface of an ice sheet are transformed into air hydrates below a certain depth Their volume and number varies partly with environment and climate. Air bubbles and hydrates at 120-2200 m depth in the Dome Fuji (Dome F) ice core were examined with a microscope. This depth range covers the Holocene/Last Glacial/Last Interglacial/Previous Glacial periods. No air bubbles were seen below about 1100 m depth, and air hydrates began to appear from about 600 m. The observed number of air bubbles and hydrates was similar to that found in the Vostok ice core. For the ice covering the Last Glacial Maximum period, however the hydrate concentration in the Dome F core is about half that of the Vostok core. Reference to snow metamorphism and packing does not explain this finding.

scholarly journals Comparison of past and future simulations of ENSO in CMIP5/PMIP3 and CMIP6/PMIP4 models

2020 ◽  
Vol 16 (5) ◽  
pp. 1777-1805
Author(s):  
Josephine R. Brown ◽  
Chris M. Brierley ◽  
Soon-Il An ◽  
Maria-Vittoria Guarino ◽  
Samantha Stevenson ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Southern Oscillation ◽  
Glacial Maximum ◽  
Last Interglacial ◽  
Future Projections ◽  
Last Glacial ◽  
Precipitation Response ◽  
Wide Range ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. El Niño–Southern Oscillation (ENSO) is the strongest mode of interannual climate variability in the current climate, influencing ecosystems, agriculture, and weather systems across the globe, but future projections of ENSO frequency and amplitude remain highly uncertain. A comparison of changes in ENSO in a range of past and future climate simulations can provide insights into the sensitivity of ENSO to changes in the mean state, including changes in the seasonality of incoming solar radiation, global average temperatures, and spatial patterns of sea surface temperatures. As a comprehensive set of coupled model simulations is now available for both palaeoclimate time slices (the Last Glacial Maximum, mid-Holocene, and last interglacial) and idealised future warming scenarios (1 % per year CO2 increase, abrupt four-time CO2 increase), this allows a detailed evaluation of ENSO changes in this wide range of climates. Such a comparison can assist in constraining uncertainty in future projections, providing insights into model agreement and the sensitivity of ENSO to a range of factors. The majority of models simulate a consistent weakening of ENSO activity in the last interglacial and mid-Holocene experiments, and there is an ensemble mean reduction of variability in the western equatorial Pacific in the Last Glacial Maximum experiments. Changes in global temperature produce a weaker precipitation response to ENSO in the cold Last Glacial Maximum experiments and an enhanced precipitation response to ENSO in the warm increased CO2 experiments. No consistent relationship between changes in ENSO amplitude and annual cycle was identified across experiments.

scholarly journals Reconstructing distribution of the Eastern Rock Nuthatch during the Last Glacial Maximum and Last Interglacial

2019 ◽  
Vol 13 (1-2) ◽  
pp. 3-9
Author(s):  
Masoud Yousefi ◽  
Afshin Alizadeh Shabani ◽  
Hossein Azarnivand
Keyword(s):  
Last Glacial Maximum ◽  
Species Distribution ◽  
Current Distribution ◽  
Glacial Maximum ◽  
Zagros Mountains ◽  
Last Interglacial ◽  
Distribution Models ◽  
Last Glacial ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Species distribution models have many applications in ecology, conservation, biogeography, and even paleoecology. In this study, we modeled the distribution of the Eastern Rock Nuthatch ( Sitta tephronota), a common rock dweller bird in Iranian Plateau, and determined most important climatic variables affecting the distribution of the species. We then projected the species distribution into the past, the Last Glacial Maximum (21,000 yr BP) and Last Interglacial (~120,000– 140,000 yr BP), to investigate how the species’ range would have changed through time. Results indicated that Zagros Mountains, Alborz Mountains and Kopet Dagh Mountains in the northeast of Iran are the most suitable habitats for the Eastern Rock Nuthatch. Annual mean temperature and annual precipitation identified as the most important variables in predicting the distribution of this species. During the Last Glacial Maximum, potential distribution of Eastern Rock Nuthatch was larger from its current distribution; however, the species’ climatic niche remains relatively stable since the Last Glacial Maximum. Our results also showed that during the Last Interglacial, distribution of the Eastern Rock Nuthatch was restricted to high elevations and was very different compared to its current distribution.

scholarly journals Comparison of past and future simulations of ENSO in CMIP5/PMIP3 and CMIP6/PMIP4 models

2020 ◽  
Author(s):  
Josephine R. Brown ◽  
Chris M. Brierley ◽  
Soon-Il An ◽  
Maria-Vittoria Guarino ◽  
Samantha Stevenson ◽  
...  
Keyword(s):  
Last Glacial Maximum ◽  
Southern Oscillation ◽  
Glacial Maximum ◽  
Last Interglacial ◽  
Future Projections ◽  
Last Glacial ◽  
Precipitation Response ◽  
Wide Range ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Abstract. El Niño-Southern Oscillation (ENSO) is the strongest mode of interannual climate variability in the current climate, influencing ecosystems, agriculture and weather systems across the globe, but future projections of ENSO frequency and amplitude remain highly uncertain. A comparison of changes in ENSO in a range of past and future climate simulations can provide insights into the sensitivity of ENSO to changes in the mean state, including changes in the seasonality of incoming solar radiation, global average temperatures and spatial patterns of sea surface temperatures. As a comprehensive set of coupled model simulations are now available for both palaeoclimate time-slices (the Last Glacial Maximum, mid-Holocene and Last Interglacial) and idealised future warming scenarios (one percent per year CO2 increase, abrupt four times CO2 increase), this allows a detailed evaluation of ENSO changes in this wide range of climates. Such a comparison can assist in constraining uncertainty in future projections, providing insights into model agreement and the sensitivity of ENSO to a range of factors. The majority of models simulate a consistent weakening of ENSO activity in the Last Interglacial and mid-Holocene experiments, and there is an ensemble mean reduction of variability in the western equatorial Pacific in the Last Glacial Maximum experiments. Changes in global temperature produce a weaker precipitation response to ENSO in the cold Last Glacial Maximum experiments, and an enhanced precipitation response to ENSO in the warm increased CO2 experiments. No consistent relationship between changes in ENSO amplitude and annual cycle was identified across experiments.

Sign in / Sign up

Export Citation Format

Share Document